<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<button id="bid">按钮1</button>
        <button class="bclass">按钮2</button>
        <button name="bname">按钮3</button>
        <button>按钮4</button>
        <button type="btype">按钮5</button>
        <button>按钮6</button>
		
		<script type="text/javascript">
			let btn1 = document.getElementById("bid");
			console.log(btn1);
			let btn2 = document.getElementsByClassName("bclass");
			console.log(btn2[0]);
			let btn3 = document.getElementsByName("bname")
			console.log(btn3[0]);
			let btn4 = document.getElementsByTagName("button")
			console.log(btn4[3]);
			let btn5 = document.querySelectorAll("button[type=btype]")
			console.log(btn5);
			let btn6 = document.querySelectorAll("botton")
			console.log(btn6[0]);
		</script>
	</body>
</html>
